Is GeyserMC supported?

Answer to this frequently asked question.

Yes, it is, including GeyserMC Floodgate. No additional configuration is required.

If you are using the address whitelist feature, make sure to whitelist the GeyserMC server address and enable forward-hostname as defined here.

If you still cannot join, you may need to register the address GeyserMC uses to connect to your proxy server.